Re: [DM] BEA_004

Yes, it does. thank you.
Dana


On Feb 25, 2004, at 7:55 AM, Norman Walsh wrote:

> / Daniela Florescu <danielaf@bea.com> was heard to say:
> | Data model: editorial, minor
> |
> | section 2.2. mentions parent as an example of partial function.
> | That's a wrong use of the mathematical concept of partial function.
> | A partial function is undefined on a subset of the domain (and
> | expected to raise
> | errors on this subset), while the parent function does return values 
> on
> | all the nodes. It is true that sometimes the result is the empty
> | sequence, but this
> | doesn't make it a partial function.
>
> I don't think the phrase "partial function" actually adds any value to
> the explanation. I've reworded it as follows:
>
> <p>There are some functions in the data model that return the empty 
> sequence
> to indicate that no value was available.
> We use the occurrence indicators <emph>?</emph> or
> <emph>*</emph> when specifying the return type of such functions.
> For example, a node may have one parent node or no parent.
> If the node argument has a parent, the
> <function>parent</function> accessor returns a singleton sequence.  If 
> the node
> argument does not have a parent, it returns the empty sequence.
> The signature of <function>parent</function> specifies that it returns
> an empty sequence or a sequence containing one node:</p>
>
> Please let me know if this satisfies your concern.
>
>                                         Be seeing you,
>                                           norm
>
> -- 
> Norman.Walsh@Sun.COM / XML Standards Architect / Sun Microsystems, Inc.
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Received on Wednesday, 25 February 2004 11:51:59 UTC